Morfometría y tabla de vida de Bactericera cockerelli (Sulc) en dos variedades de jitomate en invernadero.

Se evaluó el efecto de dos variedades de jitomate (“Charanda F1” y “Rafaello”) en la morfometría de B. cockerelli (Sulc). Se colectaron huevos, ninfas y adultos criados en dos variedades de jitomate “Charanda F1” y “Rafaello”, en condiciones de invernadero en el Colegio de Postgraduados, Campus Montecillo, Texcoco, México, en el periodo Octubre-Diciembre 2009 – Enero-Marzo 2010. Las condiciones generales de la cría fueron: sin aplicación de agroquímicos; los adultos fueron mantenidos en jaulas individuales de marco de madera cubiertos con tela de organza, bajo un periodo de 14 h de luz, con un rango de temperatura de 10 a 25° C. En el análisis de morfometría de huevos se consideraron las variables: Longitud de Huevo (LH), Ancho de Huevo (AH) y Longitud de Pedicelo (PED). En ninfas, Largo de Cuerpo (LC), Ancho de Cuerpo (AC) y Longitud de Antenas (ANT). En adultos, Longitud de Cuerpo (LC), Ancho de Cuerpo en Tórax (ACT), Longitud de Ala (LALA), Ancho de Ala (ANALA). Se encontró que el efecto de las variedades de jitomate en la morfometría, no presenta diferencias significativas sobre la Longitud de huevos (F1, 41=0.57; p=0.4551); aunque el Ancho de huevo sí resultó afectado por la variedad de jitomate sobre la que se criaron los insectos (F1, 41=11.92; p=0.0013). Los estados ninfales, para las variables Largo de Cuerpo (F4, 324=1199.2; p<0.0001), Ancho de Cuerpo (F4, 324=900.72; p<0.0001) y Largo de Antenas (F4, 324=883.93; p<0.0001), resultaron diferenciadas en forma significativa debido a la variación de los diferentes ínstares; esta diferencia tiene implicaciones prácticas porque dichas variables podrían ser usadas como guías para diferenciar las cinco fases ninfales. La longitud del cuerpo del adulto (F1, 117=7.11; p=0.0087), se afecta cuando se cría, sobre las variedades de jitomate mencionadas. _______________ MORPHOMETRICS OF EGGS, NYMPHS, AND ADULTS OF Bactericera cockerelli (Sulc), GROWN IN TWO VARIETIES OF TOMATO UNDER GREENHOUSE CONDITIONS. ABSTRACT: The effect of two varieties of tomato (“Charanda F1” and “Rafaello”) was evaluated on the morphometrics of B. cockerelli (Sulc). Eggs, nymphs, and adults of B. cockerelli (Sulc) were collected from two varieties of tomato, “Charanda F1” and “Rafaello”, under greenhouse conditions in the Colegio de Postgraduados, Campus Montecillo, Texcoco, the State of Mexico, during the periods October-December, 2009 and January-March, 2010. The general growth conditions of the offspring were: no application of agrochemicals, adults were kept in individual cages, wood frames covered with organza cloth, under a 14 h light period, temperature range from 10 to 25 °C. For the morphometrics analysis of the eggs, the following variables were considered: egg length (LH), egg width (AH), and pedicel length (PED). For nymphs, the variables were: body length (LC), body width (AC), and antennae length (ANT). For adults, the variables were: body length (LC), body width at thorax (ACT), wing length (LALA), and wing width (ANALA). The tomato varieties were found to have the following effects on morphometrics of B. cockerelli (Sulc): no significant difference in egg length (F1,41=0.57; p=0.4551); egg width was affected by the variety of tomato (F1,41=11.92; p=0.0013). There were significant differences in nymphs depending on the instances: body length (F4,324=1199.2; p<0.0001), body width (F4,324=900.72; p=0.0001); and antennae length (F4,324=883.93; p=0.0001). These differences have practical implications, since said variables can be used as guides to differentiate the five nymph stages. Body length of the adults (F1,117=7.11; p=0.0087) is affected by the different tomato varieties mentioned.Tesis (Maestría en Ciencias, especialista en Entomología y Acarología).- Colegio de Postgraduados, 2010.Consejo Nacional de Ciencia y Tecnología (CONACyT)

Postharvest treatments for control of Conotrachelus dimidiatus (Coleoptera: Curculionidae) in guava (Psidium guajava).

Guava (Psidium guajava) is one of the most common fruit trees cultivated in Latin America; however, its production is delimited by different insect pests that affect fruit quality, including the guava weevil Conotrachelus dimidiatus. This study assessed the effects of two post-harvest treatments (hydrothermal and temperature storage) in the control of C. dimidiatus, as well as physicochemical variables of treated guava fruits. The hydrothermal treatment presented mortality of larvae 70 minutes after immersion, while mortality of larvae was observed after the six days of evaluation in the temperature treatment. In both post-harvest treatments, the variables titratable physicochemical acidity and vitamin C did not present significant statistical differences among treatments; whereas, the degrees °Brix and ionic acidity showed significant differences with respect to the control. For the hydrothermal treatment, a decrease in the time of immersion is suggested in order to minimize or void the effects of the treatment tested. Regarding temperature, it was observed that the presence of larvae of C. dimidiatus in fruit leads to a reduction in the sugar content. Hence, more studies are needed to determine ideal temperatures in which the effects of the treatments are minimal or void on the physicochemical properties of guava fruit. These may be considered as an alternative to post-harvest control for this insect

Tratamientos poscosecha para el control de Conotrachelus dimidiatus (Coleoptera: Curculionidae) en guayaba (Psidium guajava)

Guava (Psidium guajava) is one of the most common fruit trees cultivated in Latin America; however, its production is delimited by different insect pests that affect fruit quality, including the guava weevil Conotrachelus dimidiatus. This study assessed the effects of two post-harvest treatments (hydrothermal and temperature storage) in the control of C. dimidiatus, as well as physicochemical variables of treated guava fruits. The hydrothermal treatment presented mortality of larvae 70 minutes after immersion, while mortality of larvae was observed after the six days of evaluation in the temperature treatment. In both post-harvest treatments, the variables titratable physicochemical acidity and vitamin C did not present significant statistical differences among treatments; whereas, the degrees °Brix and ionic acidity showed significant differences with respect to the control. For the hydrothermal treatment, a decrease in the time of immersion is suggested in order to minimize or void the effects of the treatment tested. Regarding temperature, it was observed that the presence of larvae of C. dimidiatus in fruit leads to a reduction in the sugar content. Hence, more studies are needed to determine ideal temperatures in which the effects of the treatments are minimal or void on the physicochemical properties of guava fruit. These may be considered as an alternative to post-harvest control for this insect. &nbsp;En América Latina, la guayaba (Psidium guajava) es uno de los principales frutales cultivados, no obstante, su producción es demeritada por diversos insectos plaga, uno de ellos es el picudo de la guayaba Conotrachelus dimidiatus, el cual afecta la calidad de los frutos. En este estudio se evaluó el efecto de dos tratamientos poscosecha (hidrotérmico y temperatura de almacenamiento) en el control de C. dimidiatus y la calidad de algunas variables fisicoquímicas de los frutos de guayaba tratados. En el tratamiento hidrotérmico se presentó mortalidad de larvas a partir de los 70 min de inmersión y en el de temperatura, se observó mortalidad de larvas después de seis días de evaluación. En ambos tratamientos poscosecha, las variables fisicoquímicas acidez titulable y vitamina C, no presentaron diferencias estadísticas significativas entre los tratamientos, mientras que, los grados °Brix y acidez iónica mostraron diferencias significativas respecto al testigo. Para el tratamiento hidrótermico, se sugiere disminuir el tiempo de inmersión para que su efectos sean mínimos o nulos; en cuanto al de temperatura se observó que la presencia de larvas de C. dimidiatus en los frutos ocasiona una reducción en el contenido de azúcares de los mismos. Por lo tanto, se requieren más estudios para determinar las temperaturas óptimas para que los efectos de los tratamientos probados sean mínimos o nulos sobre las propiedades fisicoquímicas de los frutos de guayaba y éstos puedan ser considerados como una alternativa de control poscosecha para este insecto. &nbsp